Missing Airman's Helmet

May 2, 1986

LONDON — ''Lorence.'' The name was on the helmet shown on Libyan television Thursday night. Capt. Paul F. Lorence, 31, of San Francisco, was aboard a U.S. F-111 warplane lost during the attacks against Tripoli and Benghazi on April 15. He and the pilot, Capt. Fernando L. Ribas-Dominicci, 33, of Puerto Rico, are presumed dead. The Libyan report, monitored by the British Broadcasting Corp., said the helmet washed up Thursday on a beach near Al-Zawiyah, 25 miles west of Tripoli.